Re: table.foreach NYI
- From: Finn Wilcox <finnw@xxxxxxxxxxx>
- To: luajit@xxxxxxxxxxxxx
- Date: Wed, 13 Nov 2013 02:24:38 +0000
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On 12/11/2013 22:39, Mike Pall wrote:
> but better check if the workaround isn't slower than the
> interpreter ...
>
It's not just about the speed of the next() function. Splitting the
trace has other side effects (forcing FFI scalar types to be boxed,
preventing allocation sinking, redundant int32_t->lua_Number->int32_t
conversions...)
And yes you can create a temporary array but that has its own costs -
Suspend the GC (commit charge) or keep it active (more cache misses)
And as for the speed of the next() function - I assume it is mostly
due to the branches necessary for probing hash slots?
Maybe one could do some bit twiddling to probe multiple slots in parallel?
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